Armature wedge driver and remover



Oct. 25, 1949. TERRY 2,485,992

ARMATURE WEDGE DRIVER AND REMOVER Filed Feb. 27, 1945 IN V EN TOR. J'OZ LESLIE TEE/P) Patented Oct. 25, 1949 ARMATURE WEDGE DRIVER AND REMOVER Joel Leslie Terry, Anderson, S. 0., assignor to Buchanan Electrical Products Corporation, a corporation of New Jersey Application February 27, 1945, Serial No. 579,926

This invention relates to a tool for installing or removing insulating wedges in or from the winding receiving slots of a rotor r stator.

Certain types of electric motors are characterized by rotors or stators or both which have parallel slots formed therein for the reception of the armature or field windings, as the case may be. After the windings have been placed in the slots it is necessary in many cases to close the open ends of the slots to protect the windings therein. For this purpose narrow dielectric strips or wedges are driven into the slots to cover the windings.

One manner of driving the wedges into place employs a guide by which the wedge can be aligned with the slot. The wedge is then engaged at its free end with a metal strip of approximately the same size as the wedge. The metal strip is then tapped with a hammer until the wedge is driven home. When it is desired to remove a wedge from its slot in the rotor or stator, it is driven therefrom by the metal strip. This method of wedge installation or removal has a number of drawbacks. It is difllcult to hold the wedge guide and metal strip while tapping on the metal strip with a hammer. Also, as the metal strip is in most cases necessarily quite thin, and does not have accordingly sufiicient rigidity to withstand hard blows from the hammer, only relatively light blows can be struck, making the period of complete installation over long. Also it is not physically possible to strike the metal strip more than a relatively few number of blows per unit of time.

It is accordingly among the objects of this invention to provide a tool with which wedges as described above may quickly and easily be installed in Or removed from slots in a rotor or stator. Another object is to provide a tool of the above nature which is simple, inexpensive and rugged in construction, and which is readily usable by unskilled personnel. Other objects will be in part apparent, and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements and arrangements of parts, as will be exemplifled in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claim.

In the drawing, wherein I have shown one form of my invention,

Figure l is an elevation of the tool attached to a pneumatic hammer, a portion of the hammer being broken away and shown in section to illus- 1 Claim. (Cl. 29-203) trate the manner of attachment of the tool thereto;

Fiigure 2 is a fragmentary top plan View of the too Figure 3 isa section taken along the line 3-3 of Figure 1; and

Figure 4 is another side elevation of the tool, but showing itin a different operative position.

Similar reference characters refer to similar parts throughout the views of the drawing.

Referring first to Figure 1, a pneumatic hammer, of a conventional type, is generally indicated at it, the hammer being channeled as at It to receive the shank l2 of my tool, which is generally indicated at l3. As will be described in detail hereinbelow, the tool includes a portion adapted to slidably fit within the channel M of a guide l5 so that when the hammer is operated the tool drives a wedge l6 into a slot ll formed in a rotor or stator l8.

Tool shank I2 has fastened thereto a spring l9 which may be threaded on the lower end 29 of hammer ill to attach tool I3 to the hammer. Also fastened to the tool shank is a collar or the like 2| which, by reason of the tension of spring I9, is drawn against the end 20 of the hammer when the air pressure within the hammer drops. Thus when air is admitted to hammer I 0, as by depression of a button 22, tool I3 is rapidly reciprocated by the hammer.

The body 23 of tool I3 is fastened in any convenient manner to the free end of shank I2 and, as shown in Figure 3, is relatively thin so as to permit of ready passage along a slot 24 in guide 15. On the bottom of tool body 23 is integrally formed an elongated flat plate 25 which lies at right angles to the body of the tool and has substantially the same cross sectional dimensions as wedge I6. Plate 25 is slightly smaller in cross section than slot l5 so as readily to slide therealong. The upper edge 26 of tool body 23 (Figure 1) is preferably curved, and a suitable number of teeth 2'! are cut in this edge. The toothed portion of edge 26 terminates as at 28 slightly above plate or blade 25, s0 as to be well above the point of engagement between the blade and wedge l6 when the tool is being used to drive the wedge into rotor or stator 18.

While body 23 of tool l3 may be attached to shank l2 in any suitable manner, I have found it convenient to cut out thebo-dy as at 29, thus providing an abutment or shoulder 30 against which the end of shank I2 is set when the shank and body are attached as by welding or brazing. Thus the full effect of the impact from hammer I0 is transferred to tool body 23 and accordingly to wedge Hi In Figure 1, I have shown the tool being used to install a wedge in the rotor or stator. Thus wedge I6 is placed in guide [5, and the channel 14 of the guide is aligned with slot H in rotor l8. As the wedge is slightly shorter than the guide, there is a suflicient length of channel I 4 at the 'r ight harid end thereof to; accommodate entrance of" tool' blade" or plate 25. Thus the guide I5 may be held by one hand, while hammer I0 is held by the other. Upon depression of button 22 the pneumatic hammenoauseswtool blade 25 to strike rapid, repeated blows on the edge of wedge l6, driving the wedge 'c iiiickl-y intd its slot.

moval of the wedge, it is turned over, as shown in Figure 4, so that the serrationsaortteetha21mm body 23 may be engaged with the top of Wedge [6. Thus when the hammer I0 is operatedfltlfteth bite into the top of the wedge and accordingly 'gr'ip it se'curely enougn tottransferiithe hamm'er impacts so that the wedge may quickly andzeasily be driven outon its 'sl'ot.

Thus it may be seen that I have provided a rotor 61 stator wedgeninstaumgr oi rmoving tbl "that attains the several objects set 'fortlr' hereinabove in a=thoroughly prabtieal and eflicint ma-nner.

As -many plissibl embddiments may be made 1 of- 1 the ab eve "-inventiong and as niany-" ehariges might"be-made in the enibodiment;above setfbrth, it'i's te*be'=unde"rst0od tHat- 'alI- rnattei hereinb'e'fore 's'et forth or' showri irr-the accompanying drawing 10 diameter greater than the thickness of said blade land a longitudinal straight line axis angularly I adispesedainrrelationr to the chord corresponding to said arcuate 'dge.

- JOEL LESLIE TERRY.

" 'REFERENCES CITED l li following references are of record in the file-oii this patent:

20 UNITED STATES PATENTS 4: Number Name QllcDate 571;,400 4, Ruppert-w, .I -Y Nomi. 151,; 1896 means WBoppenhusen \MayfL'LLlQO l 

